Telephone system.



'PATENTEDNOV. 20, 1906. F. R. PARKER.

TELEPHONE SYSTEM.

APPLIUATION FILED JULY27. 1903.

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FREDERICK R. PARKER, OF LA FAYETTE, INDIANA.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Nov. 20, 1906.

Application filed July 27, 1903. Serial No. 167,189.

To aZZ whom it may concern:

Be it known that I, FREDERICK R. PARKER, a citizen of the United States, residing at La Fayette, in the county of Tippecanoe and State of Indian a, have invented new and useand at the same time to furnish the sub scribers stations with individual or local sources of current for the respective substation-transmitters.

In my present invention I have shown a telephone system wherein a telephone-line extends from a substation to a central station, where it terminates in suitable connection-terminals. A signaling device is asso ciated with the line at the central station, so that it operates over the metallic circuit of the line when no connection is made with the line, thus giving the signal for connection, and over a grounded return or common return circuit of the line when'connection is made with the line, thus giving the signal for disconnection. The signaling device is associated with. a central source of electricity for operating the same. The substation is provided with a local-battery circuit f or supplying. the substation-transmitter with talkingcurrent, The plug-cord circuit is simply a means of connecting subscribers lines together, there being no signaling devices nor source of electric current normally associated Y therewith.

I have illustrated my invention in the accompanying drawing, in which are shown two subscribers lines-and the central-station signaling and connecting apparatus.

The line of subscriber A extends in two limbs j and 7c from a substation to the central station, where the said limbs terminate in the connection-terminals Z and 0, respectively, of the spring-jack I. Contact m of the said spring-j ack normally makescontact with ter- 5 mmal Z andis connected to pole t of battery M through conductor g, visual lamp 8, and

conductor v. Contact 7 of the said jack is conductively connected to contact m and is adapted to make contact with terminal 0 of the said jack when connection is made with the line. Contact n of the said jack normally makes contact with terminal 0 and is connected to pole at of battery M through conductor 1". Pole u of battery M is also connected to ground through conductor g. Terminals Z and 0 are adapted to disengage contacts m and n, respectively, when connection is made with the line. I have preferably shown avisual lamp 8 for the signaling device, but desire it to be understood that any other form of signaling device may be used instead. I have also shown a battery M for the central source of current, but desire it to be understood that any other source of electricity may be used. instead of the said battery. A battery is not essential, as the central source of electricity, for in this invention it does not send out any current over the telephone-line during conversation over the said line. Therefore any electric generator may be used to give the signaling-currents and will not interfere with conversation over the said line.

At the substation A the limb is of the line is normally connected to ground through switch-hook f and conductor 9. Ringer h and condenser 'L are normally bridged across the limbs of the telephone-line through the switch-hook f. Limb j of the telephone-line is connected in circuit with receiver a and winding 6 of repeating-coil C. Battery a, transmitter 19, and winding d of repeatingcoil C are connected in series, and one'pole of battery 0 is connected to switch-hook When the receiver a is taken from the switchhookf, the ground 9 and ringer h are disconnected. from the switch-hookf, and the windings e and (Z of repeating-coil G are connected to the said switch-hook in a manner well understood.

The apparatus and connections for line B (shown upon the right of'the drawing) are the same as for line A, and like characters have been employed for indicating like parts.

In theplug-cord circuit the tip-contact u of connecting-plug K is connected through tipstrand a spring 11, of listening-key F, contact 1' winding t, of repeating-coil H, contact k spring Z and sleeve-strand v to'sleeve-contact 1),. Likewise tip-contact 0c, of connecting-plug L is connected through tip-strand m spring 0 of ringing-key G, contact 10,,

winding 8 of repeating-coil H, contact 9,, spring 1",, and sleeve-strand 11 to sleeve-contact y Contact m, of listening-key F is connected, through conductor w ,operators receiver a and winding 6 of repeating-coil D, to contact 7L Contact h of listening-key F is also connected in circuit with winding (1 of repeating-coil D, operators transmitter 7),, battery and contact Ringing-generator E has one of its terminals connected to ground through conductor g and its other terminal connected to contact n, of ringingkey G. When listening-key F is depressed, springs i and Z disengage contacts j, and k respectively, and engage contacts h and m respectively. Contact h, also engages contact f When ringing-key Gis depressed, springs 0 and r disengage contacts 10 and g respecspring 0 to engage contact 1).

tively, and spring 0 engages contact 71,. preferably employ a repeating-coil H in the plug-cord circuit, but desire it to be understood that the said repeating-coil may be replaced by the well-known equivalent condensers.

If subscriber A desires to talk with subscriber B, he lifts his telephone-receiver a from the switch-hookf in the usual manner,

thereby closing the circuit of battery M through conductor '1), visual lamp 8, conductor q, contact-m of spring-jack I, ack-spring Z, limb of the telephone-line, receiver a, winding 6 of repeating-coil C, switch-hook limb is of the telephoneline, jack-spring 0, contact n and conductor 1", and causing visual lamp 8 to light, and thereby convey to the operator the signal for connection. By removing the receiver a from the switch-hook f the subscriber also closes the circuit through battery 0, transmitter b, winding d of repeating-coil C, and switch-hook f, which supplies his transmitter b with current for talking purposes. The operator thereupon inserts the answering-plug K into the spring-jack I of line A, thereby causing jack-springs Z and 0 to disengage contacts m and n, resp ctively, and he circuit of battery M, including visual lamp 8, is now broken between contact n and jack-spring 0 and also between contact m and jack-spring Z, and the said visual lamp is thus rendered inoperative. The operator then depresses her listening-key F, and thereby bridges her receiver (1 and winding 6 of repeating-coil D across the talking-strands u, and v, of the plug-cord circuit, and at the same time disconnects the winding 25, of repeating-coil H from the said talking-strands a, and '0 By depressing the listening-key F the operator also closes the circuit through contact h "contact f battery 0 transmitter b and winding (1 of repeating-coil D, which supplies her transmitter with current for talking purposes. After learning that subscriber B is the subscriber called for the operator inserts the calling-plug L into a spring-jack I of line B, and thereby causes jack-springs land 0 thereof to disengage contacts m and n, respectively, and ack-spring 0 to engage contact p, and thus close the circuit of battery M, from ground at g,, through conductor v, visual lamp s, conductor (1, contact p, jackspring 0, limb 7c of the telephone line and switch-hook f, to ground at g, which causes the visual lamp 8, belonging to line B, to operate and convey a signal to the operator. The operator then depresses the ringing-key G, and thereby closes the circuit of ringing-generator E from ground at 9 through contact n spring 0 tip-strand m tip-contact 90 jackspring Z of line B, limb of the telephone-line, condenser 'L, ringer 7L, and switch-hookf, to ground at g, thus sending a ringing-current through ringer h, and, thereby causing it to signal subscriber B. When the operator depresses the ringingkey G, she also restores listening-key F to its normal position. When subscriber B responds and lifts his receiver a from the switch-hook f, he breaks the circuit of battery M through visual lamp 8, between the switch-hook f and ground g, and thereby extinguishes the signal oflampsandrenderssameinoperative. Subscriber B by taking the receiver a from the switch-hook f closes the circuit from limb j of the telephone-line, through receiver a,winding e ofrepeating-coil C and switch-hook f, to limb 7c, and also the circuit of battery 0 through transmitter b, winding d of repeating-coil C and switch-hookf, which supplies the transmitter b with current for talking purposes. Subscribers A and B are now connected for conversation. The talking-currents from transmitter b of substation A are repeated through repeating-coil C to the metallic line.

of subscriber A, and thence are repeated through repeating-coil H to the line of subscriber B and substation B. The talkingcurrents from transmitter b of substation B are repeated through repeating-coil C to the metallic line of subscriber B, and thence are repeated through repeating-coil H to the line of subscriber A and substation A. During.

conversation over lines A and B one pole t of battery M is connected with the repective lines at the respective jack-contacts p p of the said lines, but no current from battery M is allowed to flow.

When conversation is completed and subscriber A hangs his receiver a on the switchhook f, he disconnects the said switch-hook from the windings d and e of repeating-coil C and connects it with ground g. This closes the circuit of battery M from ground at 9 through conductor 1), visual lamp 8, conductor g, contact p, jack-spring 0, limb k of the telephoneline, and switch-hook f, to ground at g, thus causing the said visual lamp to operate and convey to the operator the signal for disconnection. When subscriber B hangs his receiver (1 upon the switch-hook f, he conveys to the operator his signal for disconnection in a manner similar to that just described for subscriber A. When the opertor receives both disconnect -signals, she withdraws the connecting-plugs K and L from their respective springq' acks, and thereby restores both telephone-lines and all central-station circuits and apparatus to their normal condition. The visual lamps s s are rendered inoperative by having their respective circuits broken at the contacts 19 p of their respective spring-j acks.

While I have herein shown a visual lamp as the line and supervisory signal, it is evident that any other form of signaling device such as a relay controlling a lamp, an annunciator having a visual signal, or any electrically-operable device-may be used in place of the visual lamp.

While I have illustrated my present invention in connection with particular types of spring-jacks, connecting-plugs, keys, signaling devices, and sources of electric current, I do not wish to confine this invention to such particular apparatus, but desire it to be understood that different forms of these several pieces of apparatus may be used.

While this invention is illustrated in connection with a switchboard of the single type, it is to be understood that its features may be adapted to switchboards of the transfer series, multiple, or divided board type.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The combination with a metallic telephone-line and connection-terminals connected thereto, of a signaling device connected to the said line, a central source of electricity connected to thesaid device and also to the said line, a plug-cord circuit adapted to be conductively connected with the said line, means for closing the circuit of the said source through the said signaling device and the metallic telephone-line, when no connection is made with the line, and thereby operating the said device as aline-signal, and means for closing the circuit of the said source through the said device and a limb of the telephone-line, with a suitable return, when connection is made with the line, and thereby operating the said device as a supervisory signal, substantially as described.

2. The combination with a telephone-line and connection-terminals connected thereto, of a signaling device connected to a limb of the said line, a central source of electricity connected with the said device and normally with a limb of the said line, a plug-cord circuit adapted to be conductively connected with the said line, the said plug-cord circuit being normally disconnected from the said central source and said signaling device, a subscribers telephone connected with the said line, a local source of electricity at the said telephone for supplying the transmitter thereof with current for talking purposes, the said central source being used for operating the said signaling device only, means whereby the subscriber, upon lifting his receiver from the switch-hook,-closes the circuit of the said central source through the said signaling device and the limbs of the telephone-line and thereby operates the said signaling device as a line-signal, when no connection is made with the line, and means whereby the subscriber, upon hanging his receiver on the switch-hook, closes the circuit of the said central source through the said signaling device and a limb of the telephone-line, with a suitable return, and thereby operates the said signaling device as a supervisory signal, when connection is made with the line, substantially as described.

3. The combination with a telephone-line and connection-terminals connected thereto, of a signaling device associated with the said line, a source of electricity associated with the said device and said line, a plug-cord circuit adapted to be conductively connected to the connection-terminals of the line, means whereby, when the said connection is made with the line, the circuit of the said signaling device is changed from the metallic circuit of the line to a grounded return-circuit of the line, substantially as described.

4. The combination with a telephone-line and connection-terminals connected thereto,

of a signaling device at the central station connected with the said line, a central source of electricity associated with the said device and normally with the said line, and adapted for supplying electric current for operating the said signaling device, but not for supplying current for talking purposes, a plug-cord circuit adapted to be conductively connected with the said line, a subscribers telephone, including a local battery for supplying the transmitter thereof with current for talking purposes, at a substation, connected .to the said line, means whereby the subscriber closes the circuit of the said central source through the said signaling device, and the metallic circuit of the line, and thereby causes the said device to display a line-signal when no connection is made with the line, means whereby the plug-cord circuit renders the said signaling device inactive, when connection is made with the line and the subscriber has his receiver removed from the switch-hook, means whereby the operation of connecting the plug-cord circuit with the telephone-line causes the said signaling de vice to be changed from a line-signaling circuit to a supervisory signaling-circuit, and means whereby the subscriber closes the circuit of the said source through the said signaling device and a common return-circuit of the line, and thereby causes the said device to display a supervisory signal, when connectionis made with the line, substantially as described.

5. In a telephone system, the combination with metallic telephone-lines extending from respective individual substations to the central station thereof, of a signaling device for each line and associated therewith, a' telephone at each substation and connected to the respective lines, a central source of cur rent for operating all of the said signaling devices, an individual source of current for each telephone, means whereby the said central source is adapted to operate the said signaling devices over the respective metallic circuits of the lines, as line-signals, means whereby the said central source is adapted to operate the said signaling devices over the respective common return-circuits of the lines, as supervisory signals, and means whereby the said telephones are operated from their respective individual sources of current, substantially as described.

6. In a telephone system, the combination with two telephone-lines extending from respective substations to the central station, of respective signaling devices associated with the said lines, a telephone for each line and connected thereto, a central source of electricity adapted to operate the said signaling devices, a plug-cord circuit adapted for connecting the said lines together for conversation over same, the said plug-cord circuit being normally freev from connection with the said signaling devices and said central source, means whereby the said central source is adaptedto operate the said devices as central-energy line-signals, over the respective metallic circuits of the lines when no connection is made with the lines, means whereby the said central source is adapted to operate the said devices as central-energy supervisory signals, over the respective grounded return-circuits of the lines when connection is made with the lines, and means whereby the said telephones are supplied with individual, local sources of current for talking purposes, substantially as described.

7. The combination with a telephone-line and connection-terminals connected thereto, of a signaling device associated with the said line, a source of electricity associated with the said signaling deviceand normally with the said line, a plug-cord circuit adapted to be conductively connected to the connectionterminals of theline, means whereby, when the said connection is made with the line, the circuit of the said signaling device and source of electricity is changed from the metallic circuit of the line to a common return-circuit of the line, substantially as described.

8. The combination with a telephone-line extending from a substation to the central station and terminating in suitable connection-terminals at the central station, of a signaling device at the central station associated with the line, a central source of electricity associated with the said device and normally with the said line, a plug-cord circuit adapted to be connected with the said line, a telephone at the substation connected to the said line, means whereby the said signaling device is under control of the sub scriber, as a line-signaling device, operating over the metallic circuit of the line, when no connection is made with the line, and as a supervisory signaling device, operating over a common returncircuit of the line, when connection is made with the line, substantially as described.

9. In a telephone system, the combination with two telephone-lines extending to the central station and terminating in suitable respective connection-terminals, of signaling devices associated with the respective lines, the said devices each being adapted to give a line-signal and a supervisory signal, a central source of electricity associated with the said devices and said lines, a plug-cord circuit terminating in two connecting-plugs and adapted to be connected with the said lines, the said plug-cord circuit being normally free from any signaling device or source of electricity and being used simply as a means of connecting the said lines together for conversation over same, and means for operating the said signaling devices, as linesignals over respective metallic circuits of the lines and as supervisory signals over respective common return-circuits of the lines, substantially as described.

10. In a telephone system, the combination with telephone-lines extending to the central station thereof, of a signaling device for each line and associated therewith, a telephone for each line and connected thereto, a central source of current for operating all of the said signaling devices, an individual source of current for each telephone, means whereby the said central source is adapted to operate the said signaling devices as central-energy line-signals, over respective metallic circuits of the lines, and also as centralenergy. supervisory signals, over respective common return-circuits of the lines, and means whereby the said telephones are operated from their respective individual sources of current, substantially as described,

IIO

11. The combination with a telephone- 13. The combination with a telephoneline, of a signaling device in series with the line, and means at a central station for changing the said series circuit from a metallic circuit of the line to a common return-circuit of the line.

14. The combination with a telephoneline, of a signaling device is series with the said line, and means at a central station whereby the circuit of the telephone-line and signaling device is changed from a metallic circuit of the line to a grounded return-circuit of the line.

15. The combination with a metallic telephone-line, of a signaling device, a source of electricity, and means at a central station whereby the signaling device and source of electricity may be put in circuit with the metallic telephone-line, or in circuit with one limb of the telephone-line and a common return, one at a time.

16. The combination with a metallic telephone-line, of a signaling device, and means at a central station whereby the signaling device may be put in circuit with the metallic telephone-line, or in circuit with one limb of the telephone-line and a common return, one at a time.

17. The combination with a metallic telephone-line, of a signaling device and source of electricity in a series circuit with the metallic line, and means at a central station whereby the signaling device and source of electricity may be placed in a series circuit with one limb only of the metallic line.

18. The combination with a metallic telephone-line, of a conductive circuit including a signaling device, and means at a central station for connecting the conductive circuit in series with the metallic telephone-line, or in series with one limb only, of the telephoneline, with a suitable return, one circuit at a time.

19. The combination with a telephone-line extending to a switchboard, of a signaling device, a source of electricity, and a switch at the switchboard whereby the signaling device and source of electricity are placed in a series circuit with the metallic telephone-line, or in a series circuit witha limb of the telephone-line and a suitable return, one circuit at a time. I

20. The combination with a metallic telephone-line extending from a substation to a central station, of a signaling device and source of electricity at the central station, a switch at the substation adapted to close the circuit between the limbs of the metallic line, and adapted to open the circuit between the limbs of the metallic line and connect one limb of the line to a common return, one at a time, and a switch at the central station, adapted to bridge the signaling device and source of electricity across the metallic line, or to connect said device and source in series .with one limb of the metallic line, one at a time, the said switches cooperating to operate the signaling device over a metallic circuit of the telephone-line, or over a common return-circuit of the telephone-line, substantially as described.

21. The combination with a metallic telephone-line extending from a substation to a switchboard, of a switch, signaling device and source of electricity associated with the line at the switchboard, a switch associated with the line at the substation, means provided at the said switches whereby the signaling device and source of electricity may be alternately connected in series with the metallic telephone-line and in series with one limb of the telephone-line, the said switches cooperating to operate the signaling device over the metallic circuit of the line, and over a common return-circuit of the line, one at a time, and each switch being arranged to operate the signaling device or render same inoperative, independent of the position of the other switch.

22. An electrical transmitting line, an electrically-operable device associated therewith, and means at a central station adapted to connect the said device in circuit with the metallic line or with a limb of the line, as desired.

23. In combination, a metallic telephoneline, a signaling device and source of electricity associated with the line, means for establishing a circuit through the said source, the metallic line and the said device, to operate the latter, when no connection is made with the line, and means for establishing a circuit through the said source, one limb only of the line and the said device, with a suitable return, to operate the latter, when connection is made with the line.

' 24. A telephone-line extending from a substation to a central station, a switch at the substation, a connection-terminal, signaling device and source of electricity, associated with the line at the central station, the said switch and connection-terminal cooperating to alternately connect the said device and source in circuit with the metallic line'or in circuit with one limb of the line and a suitable return, one at a time, to operate the said device, either the said switch or connection-terminal being adapted to operate the signaling device or render same inoperative, independent of the position of the other, substantially as described.

25. A telephone-line extending from a substation to a central station, a signaling device and source of electricity associated with the line at the central station when no connection is made with the line, and suitable circuit connections whereby the signaling device is caused to give a signal over a circuit including a limb of the line, at the moment connection is made with the line at the cen- ICO tral station while the apparatus at the sub station is not in use.

whereby the said device may be operated over a circuit including one limb only of the line, when connection is made with the line, for purposes substantially as described.

27. In an electrical transmitting system, lines extending to a central station, a common return for the lines, an electrically-operable device associated with a line at the cen tral station, and means at the central station whereby the said device may be connected in a series circuit with the limbs of the line or in circuit with one limb of the line and the common return.

28. In an'electrical transmitting system, lines extending from substations to a central station, a common return for the lines, an electrically-operable device associated with eachline at the central station, means whereby the said device may be operated over a circuit including the limbs of the line in series, when no connection is made with the line, "and means whereby the said device may be operated over a circuit including a limb of the line and the common return, when connection is made with the line, for purposes substantially as described.

29. In. an electrical transmitting system, lines extending to a central station, a common return for some of the lines, a substation on one of the lines, an electrically-operable device connected with the last-mentioned line at the central station, a normal connec tion from the line to the common return at the substation, and means whereby the said device may be operated over a circuit including the metallic line or over a circuit including one limb only of the line and the common return, to cause the display of a line-signal and a supervisory signal.

80. In an electrical transmitting system, lines extending from substations to a central station, a common return for the lines, a signaling device and source of electricity connected with one limb of one of the lines at the central station, a normal connection from the other limb of the last-mentioned line to the common return, at both the substation and central station, means whereby the said device may be operated from the substation over the metallic line to give a line-signal when no connection is made with the line, and means whereby the said device may be operated over a limb of the line to give a supervisory signal when connection is made with the line.

31. A telephone-line extending from a substation to a central station, an electricallyoperable device associated with the line at the central station, a telephone at'the substation in which a limb of the line is connected to earth while the receiver is hung upon the switch-hook, and means at the central station whereby the said device may be operated over a circuit including the said limb and earth connection when connection is made with the line.

32. In a telephone system, lines extending to a central station, a common return for the lines, a substation on one of the lines, at which there is a normal connection from the line to the common return while the apparatus of the substation 18 not in use, an electrically-operable device associated with the line at the central station, and means at the central station whereby the said device may be operated over a circuit including a limb of the line and the common return when connection is made with. the line while the substation is not in use.

33. An electrical transmitting-line extending from a substation to a central station, an electrically-operable device normally connected with one limb of the line at the central station, a normal common connection to the other limb of the line at both the substation and central station, and means whereby connection with the line operates the said device over a circuit including the last-men tioned limb only of the line.

34. In an electrical transmitting system, lines extending to a central station, a common return for the lines, a substation on one of the lines, an electrically-operable device connected with one limb of the last-mentioned line at the central station, a normal connection from the other limb of the lastmentioned line to the common return, at the substation, and means whereby connection with the line operates the said device over a circuit including the last-mentionedlimb only of the line.

35. A metallic telephone-line extending from a substation to a central station, a sig naling device at the central station, and suitable circuit connections and means at the central station whereby the said device may be connected in circuit with the metallic line or in circuit with one limb only of the line, and means at the substation for opening or closing either said circuit.

36. A metallic electrical transmitting-line extending from a substation to a central station, an electrically-operable device associated with the line, and suitable circuit arrangements and means at the central station whereby the said device may be connected in circuit with the metallic line or in circuit with one limb only of the line, and means at the substation for completing, or closing either circuit.

37. A metallic telephone-line extending from a substation to a central station, a signaling device and source of electricity at the central station, and suitable circuit connections and means at the. central station whereby the said device and source may be connected in circuit with the metallic line or in circuit with one limb only of the line, and means at the substation for opening or closing either said circuit.

38. A metallic electrical transmitting-line extending from a substation to a central station, an electrically-operable device and source of electricity associated with the line, and suitable circuit arrangements and means atthe central station whereby the said device and source may be connected in circuit with the metallic line or in circuit with one limb only of the line, and means at the substa tion for completing, or closing either circuit.

39. The combination with a metallic telephone-line, of a signaling device in series therewith, and means at a central station whereby the signaling device may be placed in a series circuit with one limb only of the metallic line.

40. A metallic electrical transmitting-line extending from a substation to a central station, an. electricallyoperable device associated with the line, suitable electrical supply for the said device, and manually-operable means at both the substation and central station cooperating to operate the said device over the metallic circuit of the line or over a common return-circuit including a limb of the line.

41. A metallic electrical transmitting-line extending from a substation to a central station, anelectrically-operable device associ ated with the line, suitable electrical supply for the said device, a switch at both the-sub station and central station cooperating to operate the said device over the metallic circuit of the line or over a common return including a limb of the line, and a circuit arrangement such that each switch may oper ate the said device or render same inoperative independently of the position of the other switch,

42. In an electrical system, a three-limbed electrical line extending from one station to another, an electrically-operable device associated. with the line, suitable electrical supply for the said device, means for operating the saiddevice over limbs one and two of the line in series to give a signal, and means for operating the said device over limbs one and three of the line to give another signal, one of the limbs other than limb onebeing a com mon connection for other lines of the system.

43. A telephone-line extending from a substationto a central station, a signaling device and source of electricity associated with the line at the central station when no connection is made with the line, and suitable circuit connections whereby the signaling device is caused to give a signal over a circuit includinga limb of the line, when connection is made with the line at the central stat1on before an initiative call has been sent from the substation to the central station.

In witness whereof I have hereunto subscribed. my name this 23d day of July, A. D. v 

